[Mesa-dev] [PATCH 2/2] glsl: Teach basic block analysis about break/continue/discard.

[Kenneth Graunke]

On 04/23/2013 10:25 AM, Paul Berry wrote:
> Previously, the only kind of ir_jump that would terminate a basic
> block was "return".  However, the other possible types of ir_jump
> ("break", "continue", and "discard") should terminate a basic block
> too.  This patch modifies basic block analysis so that it terminates a
> basic block on any type of ir_jump, not just ir_return.
>
> Fixes piglit test dead-code-break-interaction.shader_test.
> ---
>   src/glsl/ir_basic_block.cpp | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/src/glsl/ir_basic_block.cpp b/src/glsl/ir_basic_block.cpp
> index 86e0cf7..2cbc682 100644
> --- a/src/glsl/ir_basic_block.cpp
> +++ b/src/glsl/ir_basic_block.cpp
> @@ -77,7 +77,7 @@ void call_for_basic_blocks(exec_list *instructions,
>   	 callback(leader, ir, data);
>   	 leader = NULL;
>   	 call_for_basic_blocks(&ir_loop->body_instructions, callback, data);
> -      } else if (ir->as_return() || ir->as_call()) {
> +      } else if (ir->as_jump() || ir->as_call()) {
>   	 callback(leader, ir, data);
>   	 leader = NULL;
>         } else if ((ir_function = ir->as_function())) {

That was a lot easier than I feared!  Nice work.

Both patches are:
Reviewed-by: Kenneth Graunke <kenneth at whitecape.org>